Grab bar



FIG. 1 is a perspective view of front, top plan and right side of a grab bar according to our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom view thereof.

The portions of the article in broken lines are shown for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a grab bar, as shown and described. 